JP5010841B2 - Ni3Si-Ni3Ti-Ni3Nb multiphase intermetallic compound, method for producing the same, high-temperature structural material - Google Patents

Description

The present invention relates to a Ni ₃ Si—Ni ₃ Ti—Ni ₃ Nb-based multiphase intermetallic compound, a method for producing the same, and a high-temperature structural material comprising a Ni ₃ Si—Ni ₃ Ti—Ni ₃ Nb-based multiphase intermetallic compound. .

In recent years, there has been a demand for improved thermal efficiency due to energy problems and effective use of resources. In order to improve thermal efficiency, there is a need for high-temperature structural materials that can be used at higher temperatures.
The mainstream of current high temperature structural materials is Ni-base superalloys. In the Ni-base superalloy, 35 vol% or more of the constituent phases is a metal phase (γ phase). It is considered difficult to increase the melting point and high-temperature creep strength of a material containing a metal phase such as a Ni-base superalloy.
In order to create a high-temperature structural material having a higher melting point and high-temperature creep strength than current high-temperature structural materials, it is conceivable to use intermetallic compounds. This is because some intermetallic compounds exhibit inverse temperature dependence of strength, and using intermetallic compounds exhibiting inverse temperature dependence can create high-temperature structural materials with high melting points and high-temperature creep strength. This is because it is expected.

However, intermetallic compounds generally have the disadvantage that they are difficult to process due to their poor deformability. It is also desired to further increase the strength in a wide temperature range from room temperature to high temperature.
This invention is made | formed in view of the situation which concerns, and provides the multiphase intermetallic compound (multiintermetallics) which has high intensity | strength and a deformability in the wide temperature range from room temperature to high temperature.

Means for Solving the Problems and Effects of the Invention

That is, according to the present invention, Si: 1 to 10.5 at%, Ti: 5 to 16 at%, Nb: 0 to 10 at%, B: 0 to 1000 ppm by weight, the balance is made of Ni except for impurities, and L1 A multiphase intermetallic compound having a two-phase coexistence structure consisting of _two phases and a D0 ₂₄ phase or a three-phase coexistence structure consisting of an L1 _two phase, a D0 ₂₄ phase and a D0 _a phase (hereinafter referred to as “intermetallic Also referred to as "compound").

  The inventors of the present invention have found that the intermetallic compound having the above structure has high strength and deformability from room temperature to high temperature, and has completed the present invention.

Why strength and deformability increases is not necessarily clear, it (1) L1 ₂ phase contained in the intermetallic compound of structure (Ni ₃ Si phase) and D0 ₂₄ phase (Ni ₃ Ti phase), either However, the strength at high temperature (temperature range from about 673 K to 873 K for the L1 ₂ phase (Ni ₃ Si phase) and temperature range up to about 1073 K for the D0 ₂₄ phase (Ni ₃ Ti phase)) (2) L1 ₂ phase and D0 ₂₄ phase form an interface structure with good consistency as shown in FIGS. 3 and 4. Two points are considered to be the factors.
Since the intermetallic compound of the present invention is excellent in strength and deformability from room temperature to high temperature, it can also be used as a high-temperature structural material.
In the present specification, “to” includes end points.

1. Intermetallic compound of the present invention The intermetallic compound of one embodiment of the present invention is composed of Si: 1 to 10.5 at%, Ti: 5 to 16 at%, Nb: 0 to 10 at%, B: 0 to 1000 ppm by weight, and the balance Is made of Ni, excluding impurities, and has a two-phase coexistence structure consisting of L1 ₂ phase and D0 ₂₄ phase, or a three-phase coexistence structure consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase.

Hereinafter, each component of the intermetallic compound will be described.
1-1. Multiphase structure First, the multiphase structure of the intermetallic compound of this embodiment will be described. In this specification, the term “double phase” means a plurality of phases, ie, two or more phases.
The intermetallic compound of the present embodiment has a two-phase coexisting multiphase structure consisting of L1 ₂ phase and D0 ₂₄ phase, or a three-phase coexisting multiphase structure consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase. ing. The L1 ₂ phase is a Ni ₃ Si phase, and its lattice constant a is 0.3497 nm. The D0 ₂₄ phase is a Ni ₃ Ti phase, and the lattice constants a and c thereof are 5.101 nm and 0.8307 nm, respectively. The D0 _a phase is a Ni ₃ Nb phase, and the lattice constants a, b, and c thereof are 0.5106 nm, 0.4251 nm, and 0.4553 nm, respectively.

Both the two-phase coexisting multiphase structure and the three-phase coexisting multiphase structure include the L1 ₂ phase and the D0 ₂₄ phase. The L1 ₂ phase and the D0 ₂₄ phase form an interface structure with good matching as shown in FIGS. Thus, it is considered that the formation of an interface structure with good consistency between the L1 ₂ phase and the D0 ₂₄ phase is a factor of the excellent strength and deformability of the intermetallic compound of the present invention. Also, D0 _a phase is believed to be dispersed in a matrix consisting become granular L1 ₂ phase or D0 ₂₄ phase.

1-2. Next, the Si content, the Ti content, and the Nb content contained in the intermetallic compound of the present embodiment will be described.

  The Si content, Ti content, and Nb content may be set within a range in which the intermetallic compound of the present embodiment has a two-phase coexisting multiphase structure or a three-phase coexisting multiphase structure.

  The intermetallic compound of this embodiment is No. in a specific example described later. 1-No. In order to have a three-phase coexisting multiphase structure such as 5 samples, Si: 3.1 to 9.2 at%, Ti: 5.1 to 11.2 at%, Nb: 3.1 to 9.2 at% Si: 3.6 to 8.7 at%, Ti: 5.6 to 10.7 at%, Nb: 3.6 to 8.7 at% are more preferable, Si: 4.1 to It is more preferable to use 8.2 at%, Ti: 6.1 to 10.3 at%, and Nb: 4.1 to 8.2 at%.

  Moreover, the intermetallic compound of this embodiment is No. in the specific example mentioned later. 1-No. In order to have excellent strength and elongation as in the three samples, Si: 5.1 to 9.2 at%, Ti: 5.1 to 9.2 at%, Nb: 3.1 to 9.2 at% Si: 5.6 to 8.7 at%, Ti: 5.6 to 8.7 at%, Nb: 3.6 to 8.7 at%, and Si: 6.1 to 8. 2 at%, Ti: 6.1-8.2 at%, Nb: 4.1-8.2 at% are more preferable.

  Moreover, the intermetallic compound of this embodiment is No. in the specific example mentioned later. In order to have excellent strength, elongation and oxidation resistance like two samples, Si: 7.2 to 9.2 at%, Ti: 7.2 to 9.2 at%, Nb: 3.1 to 5.1 at% More preferably, Si: 7.7 to 8.7 at%, Ti: 7.7 to 8.7 at%, and Nb: 3.6 to 4.6 at% are more preferable.

  Next, each of the Si content, the Ti content, and the Nb content will be described.

  The Si content is 1 to 10.5 at%, preferably 3.1 to 9.2 at%, more preferably 5.1 to 9.2 at%, and still more preferably 7. 2 to 9.2 at%. The specific content of Si is, for example, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9. 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3 2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4 , 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5 7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9 , 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8 2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8 9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, It is 10.2, 10.3, 10.4 or 10.5 at%. The range of the Si content may be between any two of the numerical values exemplified as the specific content.

  The Ti content is 5 to 16 at%, preferably 5.1 to 11.2 at%, more preferably 5.1 to 9.2 at%, and still more preferably 7.2 to 9. 2 at%. The specific content of Ti is 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6 0.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2 , 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8 5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7 , 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11 0.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2. , 12.3,1 4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6 , 13.7, 13.8, 13.9, 14.0, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14 .9, 15.0, 15.1, 15.2, 15.3, 15.1, 15.5, 15.6, 15.7, 15.2, 15.9 or 16.0 at%. The range of the Ti content may be between any two of the numerical values exemplified as the specific content.

  The content of Nb is 0 to 10 at%, preferably 0.5 to 10 at%, more preferably 3.1 to 9.2 at%, and further preferably 3.1 to 5. 1 at%. The intermetallic compound of the present invention preferably contains Nb, but may not contain Nb. Specific contents of Nb are 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 0.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2 , 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3 5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7 , 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6 0.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2 , 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8 0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9 or 10.0 at%. The range of the Nb content may be between any two of the numerical values exemplified as the specific content.

1-3. Content of Ni Content of Ni becomes like this. Preferably it is 77.5-81.5at%, More preferably, it is 78-82at%, More preferably, it is 78.5-80.5at%. The crystal structure of the Ni ₃ Si phase is cubic, and the crystal structure is simpler than the other two phases (Ni ₃ Ti phase and Ni ₃ Nb phase). Therefore, the intermetallic compound of the present invention is excellent in strength and deformability (ductility) when the matrix (basic phase) is a Ni ₃ Si phase. It can be seen that when Ti is contained in Ni ₃ Si, the ratio of Ni and Si is not exactly 3: 1 but becomes an intermetallic compound phase (L1 ₂ phase) when it is about 79.5: 20.5. Yes. Therefore, also in the intermetallic compound of the present invention, the Ni content is preferably close to 79.5 at%.

  The specific contents of Ni are 77.5, 77.6, 77.7, 77.8, 77.9, 78.0, 78.1, 78.2, 78.3, 78.4, 78. 5,78.6,78.7,78.8,78.9,79.0,79.1,79.2,79.3,79.4,79.5,79.6,79.7 79.8, 79.9, 80.0, 80.1, 80.2, 80.3, 80.4, 80.5, 80.6, 80.7, 80.8, 80.9, 81 0.0, 81.1, 81.2, 81.3, 81.4 or 81.5 at%. The range of the Ni content may be between any two of the numerical values exemplified as the specific content.

1-4. Content of B Content of B is 0-1000 weight ppm, Preferably it is 10-1000 weight ppm, More preferably, it is 10-800 weight ppm, More preferably, it is 25-600 weight ppm, More preferably, it is 50 ~ 500 ppm by weight. This is because when this amount of B is contained, the mechanical and chemical properties of the intermetallic compound of the present invention are improved. The intermetallic compound of the present invention preferably contains B, but may not contain B.
The specific content of B is, for example, 0, 10, 20, 25, 30, 40, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375. 400,425,450,475,500,525,550,575,600,625,650,675,700,725,750,775,800,825,850,875,900,925,950,975 or 1000 weight ppm. The range of the B content may be between any two of the numerical values exemplified as the specific content.

1-5. Specific composition of intermetallic compound The specific composition of the intermetallic compound of the present invention is, for example,
77.5Ni-10.5Si-12Ti,
(The number before the element means at%. The same shall apply hereinafter.)
77.5Ni-6.5Si-16Ti,
77.5Ni-10.5Si-7Ti-5Nb,
77.5Ni-6Si-11.5Ti-5Nb,
77.5Ni-1.5Si-16Ti-5Nb,
77.5Ni-7.5Si-5Ti-10Nb,
77.5Ni-4Si-8.5Ti-10Nb,

79.5Ni-10.5Si-10Ti,
79.5Ni-7Si-13.5Ti,
79.5Ni-4.5Si-16Ti,
79.5Ni-10.5Si-5Ti-5Nb,
79.5Ni-5Si-10.5Ti-5Nb,
79.5Ni-1Si-14.5Ti-5Nb,
79.5Ni-5.5Si-5Ti-10Nb,

81.5Ni-10.5Si-8Ti,
81.5Ni-6Si-12.5Ti,
81.5Ni-2.5Si-16Ti,
81.5Ni-8.5Si-5Ti-5Nb,
81.5Ni-4Si-9.5Ti-5Nb, or 81.5Ni-1Si-12.5Ti-5Nb.

  In addition, when the specific composition of the intermetallic compound of the present invention contains B, for example, in the specific composition of Ni, Si, Ti and Nb, “1-4. Content of B” It contains a specific amount of B.

2. Next, the manufacturing method of the intermetallic compound of this invention is demonstrated. Here, three embodiments of the method for producing an intermetallic compound of the present invention are shown. The intermetallic compound of this invention is not limited to what was manufactured with the following method.

2-1. 1st Embodiment The manufacturing method of the intermetallic compound of 1st Embodiment of this invention is Si: 1-10.5at%, Ti: 5-16at%, Nb: 0-10at%, B: 0-1000 weight ppm. The balance is made of an ingot made of Ni, excluding impurities, at _a temperature at which a two-phase coexisting state consisting of L1 ₂ phase and D0 ₂₄ phase or _a three-phase coexisting state consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase is obtained. A step of performing a homogenization heat treatment.

Hereinafter, each process included in this embodiment will be described in detail.
2-1-1. Ingot making process The ingot which is the object of the present invention is composed of Si: 1 to 10.5 at%, Ti: 5 to 16 at%, Nb: 0 to 10 at%, B: 0 to 1000 ppm by weight, and the remainder excluding impurities. Made of Ni.

  Since the composition of the intermetallic compound of the present invention finally obtained is substantially the same as that of the ingot, the explanation of the content of each element in the above "1. intermetallic compound of the present invention" The same applies to ingots.

  The method for producing the ingot is not limited. For example, the ingot can be produced by melting raw materials (Si, Ti, Nb, Ni, and B) in an arc melting furnace and casting them. For example, a non-consumable tungsten electrode can be used as the electrode used in the arc melting furnace, and a water-cooled copper hearth can be used as the mold, for example. The ingot may be produced by a method other than the above, for example, a method such as high frequency melting.

2-1-2. Homogenization heat treatment step Next, the produced ingot is subjected to a homogenization heat treatment.
Homogenization heat treatment eliminates segregation of alloy elements and eliminates the non-equilibrium phase during solidification, so that a two-phase coexisting state consisting of a stable L1 ₂ phase and a D0 ₂₄ phase, or an L1 ₂ phase and a D0 ₂₄ phase. and carried out at a temperature at which the three-phase coexistence consisting D0 _a phase. Whether the two-phase coexistence state or the three-phase coexistence state is determined by the composition of the ingot. When the ingot composition is located in a two-phase coexistence region such as region A in the state diagram 1323K shown in FIG. 1, the two-phase coexistence state occurs, and the ingot composition is in the state diagram of 1323K shown in FIG. When located in a three-phase coexistence region such as region B, a three-phase coexistence state is established.

The temperature of the homogenization heat treatment is not particularly limited, but is preferably 1348K or less in order to achieve a two-phase coexistence state or a three-phase coexistence state. Higher even temperatures (e.g., temperatures above 1373K) If you, D0 2-phase coexisting state ₂₄ phase consisting of single-phase state or L1 ₂ phase and D0 _a phase consisting of L1 ₂ phase as a solid solution in the L1 ₂ phase Because it becomes.
There is no particular lower limit to the temperature of the homogenization heat treatment, but the temperature of the homogenization heat treatment is preferably 1073K or more. This is because homogenization takes a long time at a temperature lower than this.
The specific temperature of the homogenization heat treatment is, for example, 1073, 1098, 1123, 1148, 1173, 1198, 1223, 1248, 1273, 1298, 1323 or 1348K. The temperature range of the homogenization heat treatment may be between any two of the numerical values exemplified as the specific temperature.

  The time for performing the homogenization heat treatment is not particularly limited, and may be performed only for the time necessary for homogenizing the composition of the entire ingot. The specific time for performing the homogenization heat treatment is, for example, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228. Or 240 hours. The time range of the homogenization heat treatment may be between any two of the numerical values exemplified as the specific time.

After the homogenization heat treatment, the ingot may be cooled to room temperature by natural cooling or forced cooling. The cooling may be natural cooling or forced cooling by water quenching or the like. Natural cooling may be performed, for example, by removing the ingot from the heat treatment furnace after the homogenization heat treatment and leaving it at room temperature, or after turning off the heater power of the heat treatment furnace after the homogenization heat treatment, May be performed by leaving
Through the above steps, the intermetallic compound of the present invention is obtained.

2-2. Second Embodiment A method for producing an intermetallic compound according to a second embodiment of the present invention includes Si: 1 to 10.5 at%, Ti: 5 to 16 at%, Nb: 0 to 10 at%, and B: 0 to 1000 ppm by weight. the balance being prepared an ingot made of Ni remove impurities, at a temperature which is a two-phase coexisting state of single-phase state or L1 ₂ phase and D0 _a phase consisting of L1 ₂ phase, the doubling of the homogenization heat treatment 1 subjected to heat treatment, comprises an L1 ₂ phase and 2-phase coexisting state or L1 ₂ phase composed of D0 ₂₄ phase, the step of performing a second heat treatment at a temperature at which the three-phase coexistence consisting D0 ₂₄ phase and D0 _a phase.

Hereinafter, each process included in this embodiment will be described in detail.
2-2-1. Ingot production process and first heat treatment process The ingot can be produced by the method described in the first embodiment. Against the prepared ingot, at a temperature which is a two-phase coexisting state of single-phase state or L1 ₂ phase and D0 _a phase consisting of L1 ₂ phase, a first heat treatment which also serves as a homogenizing heat treatment.

Whether the single phase state or the two-phase coexistence state is determined by the composition of the ingot and the temperature of the first heat treatment. Temperature D0 ₂₄ phase forms a solid solution in the L1 ₂ phase is lower than the temperature at which the D0 _a phase forms a solid solution in the L1 ₂ phase. Therefore, the temperature of the first heat treatment, is higher than the temperature at which the D0 _a phase forms a solid solution in the L1 ₂ phase, ingot becomes single-phase state consisting of L1 ₂ phase. On the other hand, when the temperature of the first heat treatment is such that the D0 ₂₄ phase is dissolved in the L1 ₂ phase but the D0 _a phase is not dissolved in the L1 ₂ phase, it becomes a single phase state or a two-phase coexistence state. It depends on the composition of the ingot. The composition of the ingot, when located two-phase coexistence region such as region A state diagram of 1323K shown in Figure 1, becomes a single phase state consisting of L1 ₂ phase, the composition of the ingot is shown in FIG. 1 when located 3-phase coexisting region, such as region B in the state diagram of 1323K is a two-phase coexisting state consisting of L1 ₂ phase and D0 _a phase.

From the above viewpoint, the first heat treatment is preferably performed at a temperature higher than the temperature at which the D0 ₂₄ phase is dissolved in the L1 ₂ phase and at a temperature higher than the temperature at which the D0 _a phase is dissolved in the L1 ₂ phase.

According to the embodiment shown later, D0 ₂₄ phase is found to be dissolved in the L1 ₂ phase by heat treatment at 1373K. Accordingly, the first heat treatment is preferably performed at a temperature of 1373K or higher. However, if the temperature of D0 ₂₄ phase forms a solid solution in the L1 ₂ phase may be a temperature lower than 1373K. Thus, in the first heat treatment, since the solid solution of D0 ₂₄ phase L1 ₂ phase, a first heat treatment may also be referred to as solution heat treatment.
The upper limit of the temperature of the first heat treatment is not particularly limited, but it is preferable to perform the first heat treatment at a temperature lower than the solidus temperature of the ingot. The solidus temperature of the ingot varies depending on the composition, and a specific value is appropriately determined by experiment, but is considered to be higher than 1523K. Therefore, the homogenization heat treatment is preferably performed at a temperature of 1523K or less.
As described above, the first heat treatment is preferably performed at 1373 to 1523K. The specific temperature of the first heat treatment is, for example, 1373, 1398, 1423, 1448, 1473, 1498, or 1523K. The temperature range of the first heat treatment may be between any two of the numerical values exemplified as the specific temperature.

The time of the first heat treatment is not particularly limited, the first heat treatment, so also serves as a homogenization heat treatment, the first heat treatment, the composition of the ingot is homogenized, and solid and D0 ₂₄ phase L1 ₂ phase It is necessary to carry out the time required for melting. The specific time of the first heat treatment is, for example, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228 or 240 hours. The range of the time of the first heat treatment may be between any two of the numerical values exemplified as the specific time.

2-2-2. Second Heat Treatment Step Next, the second heat treatment is performed at a temperature at which a two-phase coexistence state composed of the L1 ₂ phase and the D0 ₂₄ phase or _a three-phase coexistence state composed of the L1 ₂ phase, the D0 ₂₄ phase, and the D0 _a phase.
The temperature at which a two-phase coexisting state or 3-phase coexisting state, is the temperature at which the D0 ₂₄ phase solid solution in L1 ₂ phase in the first heat treatment is deposited. Whether it becomes a two-phase coexistence state or a three-phase coexistence state is as described in the section “2-1-2. Homogenization heat treatment step”.

The second heat treatment is a heat treatment conducted for the purpose of precipitating the first heat treatment D0 ₂₄ phase solid solution in L1 ₂ phase upon, it may be referred to as aging heat treatment.

The temperature of the second heat treatment is not particularly limited, but is preferably 1348K or less in order to obtain a two-phase coexistence state or a three-phase coexistence state. Higher even temperatures (e.g., temperatures above 1373K) If you, D0 2-phase coexisting state ₂₄ phase consisting of single-phase state or L1 ₂ phase and D0 _a phase consisting of L1 ₂ phase as a solid solution in the L1 ₂ phase Because it becomes.
There is no particular lower limit to the temperature of the second heat treatment, but the temperature of the second heat treatment is preferably 1073K or higher. This is because it takes a long time to precipitate the D0 ₂₄ phase at a temperature lower than this.
The specific temperature of the second heat treatment is, for example, 1073, 1098, 1123, 1148, 1173, 1198, 1223, 1248, 1273, 1298, 1323 or 1348K. The temperature range of the second heat treatment may be between any two of the numerical values exemplified as the specific temperature.

The time for performing the second heat treatment is not particularly limited, and may be performed only for the time necessary for precipitating the D0 ₂₄ phase. The specific time for performing the second heat treatment is, for example, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, or 96 hours. The range of the second heat treatment time may be between any two of the numerical values exemplified as the specific time.

  The combination of the temperature and time of the second heat treatment is, for example, 1073K-6 hours, 1073K-12 hours, 1073K-24 hours, 1073K-48 hours, 1073K-72 hours, 1073K-96 hours, 1123K-6 hours, 1123K-12. Time, 1123K-24 hours, 1123K-48 hours, 1123K-72 hours, 1123K-96 hours, 1173K-6 hours, 1173K-12 hours, 1173K-24 hours, 1173K-48 hours, 1173K-72 hours, 1173K-96 Hours, 1223K-6 hours, 1223K-12 hours, 1223K-24 hours, 1223K-48 hours, 1223K-72 hours, 1223K-96 hours, 1273K-6 hours, 1273K-12 hours, 1273K-24 hours, 1273K-48 Time, 1273K-72 During, 1273K-96 hours, 1348K-6 hours, 1348K-12 hours, 1348K-24 hours, 1348K-48 hours, 1348K-72 hours or 1348K-96 hours.

  For the purpose of improving the strength of the ingot, the temperature of the second heat treatment is preferably 1123 to 1323K, more preferably 1173K to 1273K, more preferably 1198 to 1248K, and the temperature of the second heat treatment is preferably It is 6 to 60 hours, more preferably 12 to 48 hours.

After the second heat treatment, the ingot may be cooled to room temperature by natural cooling or forced cooling. The cooling may be natural cooling or forced cooling by water quenching or the like. The natural cooling may be performed, for example, by removing the ingot from the heat treatment furnace for the second heat treatment and leaving it at room temperature, or by turning off the heater power supply of the heat treatment furnace for the second heat treatment and leaving the ingot in the heat treatment furnace as it is. May be performed by leaving
Through the above steps, the intermetallic compound of the present invention is obtained.

3-2. Third Embodiment A method for producing an intermetallic compound according to a third embodiment of the present invention includes Si: 1 to 10.5 at%, Ti: 5 to 16 at%, Nb: 0 to 10 at%, and B: 0 to 1000 ppm by weight. The balance is made of an ingot made of Ni, excluding impurities, at _a temperature at which a two-phase coexisting state consisting of L1 ₂ phase and D0 ₂₄ phase or _a three-phase coexisting state consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase is obtained. perform homogenization heat treatment, performing a first heat treatment at a temperature at which a two-phase coexisting state of single-phase state or L1 ₂ phase and D0 _a phase consisting of L1 ₂ phase, two-phase coexisting consisting L1 ₂ phase and D0 ₂₄ phase And a step of performing the second heat treatment at a temperature at which the three-phase coexistence state consisting of the L1 ₂ phase, the D0 ₂₄ phase, and the D0 _a phase exists.

  This embodiment is similar to the second embodiment, but unlike the second embodiment, it differs from the second embodiment in that a homogenization heat treatment is performed in advance before the first heat treatment. Yes. The homogenization heat treatment, the first heat treatment, and the second heat treatment step included in this embodiment are as described in the section of the first embodiment or the second embodiment, respectively.

In this embodiment, since the first heat treatment is not required to serve as the homogenizing heat treatment, it is possible to relatively shorten the time of the first heat treatment, the first heat treatment, cause solid solution of D0 ₂₄ phase L1 ₂ phase You can do as long as you need. The specific time of the first heat treatment is, for example, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, or 96 hours. The range of the time of the first heat treatment may be between any two of the numerical values exemplified as the specific time.

Hereinafter, specific examples of the intermetallic compound of the present invention will be described.
1. Ingot preparation process First, Ni, Si, Ti, Nb ingots (each purity 99.9 ppm by weight) were weighed so as to have 11 compositions shown in Table 1, and melted in an arc melting furnace. A sample made of an ingot was prepared by pouring into a mold. No. 2-No. Samples made of ingots with a composition in which B (boron) was added at 50 ppm by weight to the composition of No. 4 (referred to as No. 2B sample, No. 3B sample, and No. 4B sample, respectively) were also produced by the above method. . No. Samples composed of ingots having a composition in which B is added at 100 ppm by weight or 500 ppm by weight (hereinafter referred to as No. 2B (100) sample and No. 2B (500) sample, respectively). It was produced with.

The arc melting furnace was first evacuated and then replaced with an inert gas (argon gas). The electrode was a non-consumable tungsten electrode and the mold was a water-cooled copper hearth.

2. Homogenization heat treatment step Next, the sample obtained in the above step was subjected to a homogenization heat treatment. The homogenization heat treatment was performed in a vacuum at 1323 K-48 hours. After the homogenization heat treatment, the sample was left in the heat treatment furnace with the heater turned off, and the sample was taken out from the heat treatment furnace when the sample cooled to about room temperature.

2-1. Phase diagram creation Next, by observing the composition image by SEM and measuring the X-ray, 1-No. The constituent phases of 11 samples were examined. The results are shown in Table 1. According to Table 1, no. 1-No. Sample No. 5 has a three-phase coexisting multiphase structure consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase. 6-No. 8 samples, it can be seen that had duplex structure of two-phase coexisting consisting L1 ₂ phase and D0 ₂₄ phase. No. Nine samples have a single-phase structure composed of D0 ₂₄ phase. 10 and no. It can be seen that 11 samples had a two-phase coexisting multiphase structure consisting of D0 ₂₄ phase and D0 _a phase.

Next, each component phase was analyzed by SEM-EPMA (Scanning Electron Microscope-Electron Probe Micro Analyzer).
Based on the results of the above observation and analysis, a Ni ₃ Si—Ni ₃ Ti—Ni ₃ Nb pseudo ternary phase diagram at 1323K was prepared. This state diagram is shown in FIG. In FIG. 1, the two-phase coexistence region composed of the L1 ₂ phase and the D0 ₂₄ phase is indicated as “region A”, and the three-phase coexistence region composed of the L1 ₂ phase, the D0 ₂₄ phase and the D0 _a phase is represented by “region”. B ". Each side of the triangle in Fig. 1 is marked with two types of large and small scales. One large scale shows a content of 2.05 at%, and one small scale has half the content of one large scale. Indicates.

2-2. Microstructure observation (1) Microstructure observation with SEM (scanning electron microscope) 1-No. Five samples were observed for structure by SEM. The results are shown in FIGS. 2 (a) to 2 (e) show (a) No. 2 and FIG. 1 sample, (b) no. 2 samples, (c) No. 3 samples, (d) No. 4 samples, (e) No. The SEM composition image of 5 samples is shown. In the composition image of FIG. 2 (a), (b), portions of the black L1 ₂ phase (Ni ₃ Si phase), the gray portions D0 ₂₄ phase (Ni ₃ Ti phase), the white portions D0 _a phase ( Ni ₃ Nb phase). It was a structure in which needle-like or plate-like D0 ₂₄ phase and granular D0 _a phase were dispersed in the L1 ₂ phase as a matrix.
Next, no. 2B-No. The structure of the 4B sample was observed by SEM. However, no structural change was observed with B addition.

(2) Structure observation by TEM (transmission electron microscope) Two samples were observed for structure by TEM. The results are shown in FIGS. 3 (a), (b) and FIG. 3 (a) and 3 (b) show No. 1 after the homogenization heat treatment, respectively. (A) TEM-bright field image, (b) Restricted field diffraction pattern (SADP, Selected Area Diffraction Pattern) for two samples. Beam direction used in structure observation by TEM is a [011] L1 _2. FIG. 4 is a high-resolution photograph in which the vicinity of the interface between the L1 ₂ phase and the D0 ₂₄ phase in the TEM-bright field image of FIG.

Referring to FIGS. 3A and 4, it was found that the L1 ₂ phase as a matrix and the needle-like D0 ₂₄ phase have the following orientation relationship.
_{[011] L1 2 // [112} - 0] D0 24 (111) L1 2 // (0001) D0 24
(2 ^- is on the "2" and "-". Shows a state where there is less, the same.)
This is the same as the orientation relationship at the lamella interface in TiAl, and is an interface structure in which the densest surfaces are in contact with each other in parallel with the densest directions.
3 (a) and it is apparent from FIG. 4, L1 ₂ phase and D0 ₂₄ phase is found to form a good interface structure consistent.

2-3. Compression test Next, no. 1-No. A compression test was performed on five samples. The compression test was performed in a vacuum at a strain rate of 3.3 × 10 ⁻⁴ s ⁻¹ using 2 × 2 × 5 mm ³ square test pieces in the range of room temperature to 1273K.
The result is shown in FIG. FIG. 5 shows the No. after the homogenization heat treatment. 1-No. It is a graph which shows the relationship between the temperature obtained from the compression test about 5 samples, and the yield stress.
According to the graph of FIG. 5, all samples showed high 0.2% yield stress (0.2% proof stress) up to 873K, and No. at temperatures above 1073K. It can be seen that the sample 2 showed a high 0.2% yield stress.
It should be noted in the graph of FIG. 1-No. All five samples were able to perform the compression test without any problems in the whole temperature range from room temperature to high temperature. In general, since intermetallic compounds have poor deformability and many do not even exhibit compressive deformability, the graph of FIG. 5 shows that the intermetallic compound of the present invention has high deformability.

2-4. Tensile test (1) No. 1-No. Tensile test of 5 samples Next, No. 5 after the homogenization heat treatment. 1-No. Ten samples were subjected to a tensile test. The tensile test was performed in a vacuum at a strain rate of 1.67 × 10 ⁻⁴ s ⁻¹ using a test piece having a gauge portion of 10 × 2 × 1 mm ³ in the range of room temperature to 1173K.
The results are shown in FIGS. FIG. 6 shows No. 1 after the homogenization heat treatment. 1-No. It is a graph which shows the relationship between temperature and the maximum tensile strength about 5 samples. FIG. 7 shows No. 1 after the homogenization heat treatment. 1-No. It is a graph which shows the relationship between temperature and elongation about 5 samples.
According to FIG. 6, all samples showed high tensile strength. 1-No. It can be seen that three samples showed particularly high tensile strength. All samples showed high tensile strength because the L1 ₂ phase and the D0 ₂₄ phase both have an inverse temperature dependence of strength higher than room temperature. It is thought that it originates in forming. No. 1-No. The reason why the three samples showed particularly high tensile strength is considered to be due to the relatively high Si content in these samples. In 1173K, no. Two samples showed the highest tensile strength.
Regarding elongation, according to FIG. 1-No. It can be seen that the three samples showed high elongation. No. 1-No. The reason why the three samples showed high elongation is considered to be due to the relatively high Si content in these samples.
In general, intermetallic compounds have poor ductility, and most of them cannot even be subjected to a tensile test. 1-No. It is a surprising result that the three samples showed high elongation.

(2) No. 2B-No. Tensile test of 4B sample Next, No. 4 after the homogenization heat treatment. 2B-No. A tensile test was performed on the 4B sample. The tensile test was performed in a vacuum at a strain rate of 1.67 × 10 ⁻⁴ s ⁻¹ using a test piece having a gauge portion of 10 × 2 × 1 mm ³ in the range of room temperature to 1173K.

  In order to investigate the effect of B addition, 2B-No. Results of the tensile test on the 4B sample and 2-No. The tensile test results were compared for four samples. Graphs for comparison are shown in FIGS. FIG. 8 shows No. 1 after the homogenization heat treatment. 2 samples-No. 4 samples, and No. 1 in which B was added to each sample. 2B-No. It is a graph which shows the relationship between temperature and the maximum tensile strength about a 4B sample. FIG. 9 shows No. 1 after the homogenization heat treatment. 2 samples-No. 4 samples and No. 1 containing B 2B-No. It is a graph which shows the relationship between temperature and elongation about 4B sample.

Referring to FIG. 8 and FIG. For the two samples, it can be seen that the addition of B greatly improved both the tensile strength and the elongation. No. Two samples showed excellent results of about 15% in the whole temperature range in terms of elongation. No. For the three samples, it can be seen that the addition of B improved both the tensile strength and the elongation in some temperature ranges. No. For the four samples, it can be seen that even when B was added, neither the tensile strength nor the elongation was substantially improved.
Such a result was obtained in No. 4 samples, no. 3 samples, no. It is thought that it originates in the Si content increasing in order of 2 samples.

Next, no. The result of the tensile test of the 2B sample was compared with the result of the tensile test on the INCONEL 600 and INCONEL X750, which are general-purpose Ni alloys. The result is shown in FIG. FIG. 10 shows No. 1 after the homogenization heat treatment. It is a graph which shows the relationship between temperature and maximum tensile strength about 2B sample and INCONEL600 and INCONELX750 which are general purpose Ni alloys. In FIG. 10, the data on the general-purpose Ni alloy used in “Metals Handbook Ninth Edition Vol. 3, ASM, pp. 187-333, (1980)” was used.
According to FIG. It can be seen that the 2B sample exhibited higher tensile strength than the general-purpose Ni alloy currently in practical use. In particular, no. Since the 2B sample maintains high tensile strength, application as a high temperature structural material can be expected.

(3) No. 2B (100) sample and no. Tensile test of 2B (500) sample 2B (100) sample and no. A tensile test was performed on the 2B (500) sample. The tensile test is performed in a vacuum at a strain rate of 1.67 × 10 ⁻⁴ s ⁻¹ using a test piece having a gauge portion of 10 × 2 × 1 mm ³ in the range of room temperature to 1173K. It was.

  In order to investigate the difference in effect due to the amount of B added, a sample without addition of B (No. 2 sample), a sample added with 50 wt ppm of B (No. 2B sample), and a sample added with 100 wt ppm of B (No. .2B (100) sample) and the sample (No. 2B (500) sample) added with 500 ppm by weight of B were compared with each other. Graphs for comparison are shown in FIGS. FIG. 11 shows No. 1 after the homogenization heat treatment. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between temperature and the maximum tensile strength about 2 samples. FIG. 12 shows No. 1 after the homogenization heat treatment. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between temperature and elongation about 2 samples.

  Referring to FIGS. 11 and 12, it can be seen that all of the three types of samples to which B was added were superior in both tensile strength and elongation to the samples to which B was not added. In addition, the sample added with 100 ppm by weight or 500 ppm by weight showed the same results as the sample added with 50 ppm by weight for tensile strength, and added 50 ppm by weight for the elongation. The result was the same as or slightly inferior to the sample. Therefore, it was found that it was sufficient to add about 50 ppm by weight of B.

2-5. Oxidation test (1) No. 1-No. 5 Oxidation test of sample Next, No. 5 after homogenization heat treatment. 1-No. Five samples were subjected to an oxidation test. The oxidation test was performed by TG-DTA (Thermogravimetry-Differential Thermal Analysis). Specifically, the oxidation test was performed by measuring a mass increase per unit surface area of a sample when a 2 × 2 × 2 mm ³ test piece was exposed to air at 1273K.
The result is shown in FIG. FIG. 13 shows No. 1 after the homogenization heat treatment. 1-No. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and mass increase about 5 samples.
According to FIG. It can be seen that the increase in mass was smaller in the two samples than in the other samples. This is no. It shows that the oxidation resistance of the two samples was excellent.

Next, no. In order to investigate the reason why the oxidation resistance of the two samples was excellent, the cross section of the oxide film formed in the oxidation test was observed by SEM-EPMA. Furthermore, the composition of the oxide film formed in the oxidation test was analyzed using X-rays. As a result, no. In the two samples, it was found that a continuous protective oxide film of SiO ₂ was formed at the interface between the non-oxidized portion of the sample and the oxide film.
No. The protective oxide film of SiO ₂ was formed in No. 2 samples. It is considered that the two samples contained a relatively large amount of Si of 8.2 at%.

(2) No. 2B-No. Oxidation test of 4B sample Next, No. 4 after the homogenization heat treatment. 2B-No. An oxidation test was performed on the 4B sample. The oxidation test was performed by TG-DTA. Specifically, the oxidation test was performed by measuring a mass increase per unit surface area of a sample when a 2 × 2 × 2 mm ³ test piece was exposed to air at 1273K.

  In order to investigate the effect of B addition, 2B-No. The results of the oxidation test on the 4B sample, 2-No. The results of the oxidation test were compared for four samples. A graph for comparison is shown in FIG. FIG. 14 shows No. 1 after the homogenization heat treatment. 2 samples-No. 4 samples and No. 1 containing B 2B-No. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and a mass increase about 4B sample.

  According to FIG. In the two samples, the addition of B improved the oxidation resistance. 3 samples and no. It can be seen that the oxidation resistance of the four samples did not improve even when B was added. Further, in the log-log graph as shown in FIG. Two samples with 0.44, no. 3 samples were 0.49, No. It was 0.48 for 4 samples. Since it is considered that oxidation is controlled by body diffusion when the slope of the curve is 0.5, no. 3 samples and no. No. 4 samples are considered to be limited in oxidation by body diffusion. It is considered that the oxidation of the two samples is controlled by surface diffusion or grain boundary diffusion. Therefore, no. The improvement in the oxidation resistance of the two samples is thought to be due to the suppression of grain boundary diffusion due to B grain boundary segregation.

(3) No. 2B (100) sample and no. Oxidation test of sample 2B (500) 2B (100) sample and no. An oxidation test was performed on the 2B (500) sample. The oxidation test was performed by TG-DTA. Specifically, the oxidation test was performed by measuring a mass increase per unit surface area of a sample when a 2 × 2 × 2 mm ³ test piece was exposed to air at 1273K.

  In order to investigate the difference in effect due to the amount of B added, a sample without addition of B (No. 2 sample), a sample added with 50 wt ppm of B (No. 2B sample), and a sample added with 100 wt ppm of B (No. .2B (100) sample) and the sample (No. 2B (500) sample) added with 500 ppm by weight of B were compared with each other. A graph for comparison is shown in FIG. FIG. 15 shows No. 1 after the homogenization heat treatment. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and mass increase about 2 samples.

  According to FIG. 15, it can be seen that all of the three types of samples to which B was added had better oxidation resistance than the samples to which B was not added. Moreover, the sample added with 100 ppm by weight or 500 ppm by weight showed the same oxidation resistance as the sample added with 50 ppm by weight of B. Therefore, it was found that it was sufficient to add about 50 ppm by weight of B.

3. First heat treatment (solution heat treatment) step, second heat treatment (aging heat treatment) step No. after homogenization heat treatment Two samples were subjected to a first heat treatment for 1373K-2 days.

  Next, the second heat treatment was performed at 1223K. In order to examine the influence of the second heat treatment time on the structure or Vickers hardness of the sample, the time of the second heat treatment was changed to 12 hours, 24 hours, 48 hours, 72 hours, or 96 hours. In the second heat treatment, the sample was vacuum sealed in a quartz tube, held in a heat treatment furnace for a predetermined time, and then the sample was cooled in water by breaking the quartz tube in water.

(1) Microstructure observation by SEM No. 1 after the first heat treatment (without the second heat treatment) 2 samples and No. 2 after the second heat treatment for 12 hours, 24 hours and 48 hours. Two samples were observed for structure by SEM. The results are shown in FIGS. 16 (a) to 16 (d) respectively show (a) No. 1 after the first heat treatment (without the second heat treatment). 2 samples, (b) No. 2 after 1223K-12 second heat treatment. 2 samples, (c) No. 1 after the second heat treatment for 1223K-24 hours. 2 samples, (d) No. 2 after the second heat treatment for 1223K-48 hours. The SEM image about 2 samples is shown.

In FIG. 16 (a), the sample consists substantially only the L1 ₂ phase. This is because the first heat treatment is considered to D0 ₂₄ phase and D0 _a phase is due to a solid solution in the L1 ₂ phase. Note that the D0 _a phase and what appears its mark in FIG. 16 (a) is observed, it can be said that almost all are dissolved in the L1 ₂ phase. The first heat treatment, since at least D0 ₂₄ phase forms a solid solution in the L1 ₂ phase, a first heat treatment can be referred to as solution heat treatment.

According to FIG. 16 (b), the it can be seen that D0 _a phase is precipitated in a matrix consisting of L1 ₂ phase. Further, FIG. 16 (c), the said (d), the both D0 ₂₄ phase and D0 _a phase, it can be seen that precipitated in the matrix consisting of L1 ₂ phase. As described above, the second heat treatment causes other constituent phases to precipitate in the matrix. Therefore, the second heat treatment can also be called an aging heat treatment.

(2) Vickers hardness test Next, in order to investigate the relationship between the time of the second heat treatment and the Vickers hardness, No. 1 after the first heat treatment (without the second heat treatment). 2 samples and No. 2 after the second heat treatment for 12 hours, 24 hours, 48 hours, 72 hours, 96 hours. Two samples were measured for Vickers hardness.
The result is shown in FIG. FIG. 17 shows No. 2 after the second heat treatment. It is a graph which shows the relationship between the 2nd heat processing time and Vickers hardness about 2 samples.

According to FIG. 17, in the sample without the second heat treatment, the Vickers hardness was about Hv360, but the Vickers hardness increased by the second heat treatment for 12 hours, and further increased by the second heat treatment for 24 hours. Rose. In the second heat treatment for 48 hours, no further increase in the Vickers hardness was observed, and in the second heat treatment for 72 hours and 96 hours, the Vickers hardness was smaller than the value before the second heat treatment. The increase in Vickers hardness is thought to be due to age hardening. The decrease in Vickers hardness is thought to be due to the coarsening of the Ni ₃ Ti phase due to overaging.

(3) Tensile test Next, No. 2 samples, No. 1 after the first heat treatment. 2 samples and No. 2 after the second heat treatment (1223K-48 hours). Two samples were subjected to a tensile test. The tensile test was performed in a vacuum at a strain rate of 1.67 × 10 ⁻⁴ s ⁻¹ using a test piece having a gauge portion of 10 × 2 × 1 mm ³ in the range of room temperature to 1173K.

  The results are shown in FIGS. 18 shows No. after the homogenization heat treatment. 2 samples, No. 1 after the first heat treatment. 2 samples, No. 2 after the second heat treatment (1223K-48 hours). It is a graph which shows the relationship between temperature and the maximum tensile strength about 2 samples. FIG. 19 shows the No. after the homogenization heat treatment. 2 samples, No. 1 after the first heat treatment. 2 samples, No. 2 after the second heat treatment (1223K-48 hours). It is a graph which shows the relationship between temperature and elongation about 2 samples.

  According to FIG. 18, it can be seen that the sample after the first heat treatment had a higher tensile strength than the sample after the homogenization heat treatment in a high temperature region of 673 K or higher. It can also be seen that the sample after the second heat treatment showed the highest tensile strength among the three samples in the entire temperature range.

  According to FIG. 19, it can be seen that the sample after the first heat treatment was larger in elongation than the sample after the homogenization heat treatment in a temperature range other than room temperature. It can also be seen that the sample after the second heat treatment was larger in elongation than the sample after the first heat treatment at a temperature other than 672K. It can also be seen that the sample after the second heat treatment was larger in elongation than the sample after the homogenization heat treatment in the entire temperature range.

  From the above results, it can be seen that both the tensile strength and the elongation could be increased by the first heat treatment. Further, it can be seen that the second heat treatment can further increase the tensile strength without substantially reducing the elongation.

FIG. ₃ shows a Ni ₃ Si—Ni ₃ Ti—Ni ₃ Nb pseudo-ternary phase diagram at 1323 K, made from various specific examples of intermetallic compounds according to the present invention. (A) to (e) are specific examples of intermetallic compounds according to the present invention. 1 sample, (b) no. 2 samples, (c) No. 3 samples, (d) No. 4 samples, (e) No. 5 shows SEM images of 5 samples. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. (A) TEM-bright field image and (b) limited field diffraction pattern (SADP) for two samples. Is a high-resolution photograph of an enlarged vicinity of the interface between the L1 ₂ phase and D0 ₂₄ phase of Figure 3 TEM-in bright field image of (a). No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 1-No. It is a graph which shows the relationship between temperature and compressive yield stress about 5 samples. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 1-No. It is a graph which shows the relationship between temperature and the maximum tensile strength about 5 samples. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 1-No. It is a graph which shows the relationship between temperature and elongation about 5 samples. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 2 samples-No. 4 samples, and No. 1 in which B was added to each sample. 2B-No. It is a graph which shows the relationship between temperature and the maximum tensile strength about a 4B sample. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 2 samples-No. 4 samples and No. 1 containing B 2B-No. It is a graph which shows the relationship between temperature and elongation about 4B sample. No. 1 containing B after homogenization heat treatment, which is a specific example of the intermetallic compound according to the present invention. It is a graph which shows the relationship between temperature and maximum tensile strength about 2B sample and INCONEL600 and INCONELX750 which are general purpose Ni alloys. A specific example of the intermetallic compound according to the present invention, No. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between temperature and the maximum tensile strength about 2 samples. A specific example of the intermetallic compound according to the present invention, No. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between temperature and elongation about 2 samples. No. 1 after the homogenization heat treatment which is a specific example of the intermetallic compound according to the present invention. 1-No. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and mass increase about 5 samples. A specific example of the intermetallic compound according to the present invention, No. 2 samples-No. 4 samples and No. 1 containing B 2B-No. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and a mass increase about 4B sample. A specific example of the intermetallic compound according to the present invention, No. No. 2 containing 50 wt ppm, 100 wt ppm and 500 wt ppm B, respectively. It is a graph which shows the relationship between the atmospheric exposure time in 1273K, and mass increase about 2 samples. (A) to (d) are specific examples of the intermetallic compound according to the present invention. (A) No. 1 after the first heat treatment (without the second heat treatment) 2 samples, (b) No. 2 after 1223K-12 second heat treatment. 2 samples, (c) No. 1 after the second heat treatment for 1223K-24 hours. 2 samples, (d) No. 2 after the second heat treatment for 1223K-48 hours. The SEM image about 2 samples is shown. No. 2 after the second heat treatment, which is a specific example of the intermetallic compound according to the present invention. It is a graph which shows the relationship between the 2nd heat processing time and Vickers hardness about 2 samples. A specific example of the intermetallic compound according to the present invention is No. 1 after the homogenization heat treatment. 2 samples, No. 1 after the first heat treatment. 2 samples, No. 2 after the second heat treatment (1223K-48 hours). It is a graph which shows the relationship between temperature and the maximum tensile strength about 2 samples. A specific example of the intermetallic compound according to the present invention is No. 1 after the homogenization heat treatment. 2 samples, No. 1 after the first heat treatment. 2 samples, No. 2 after the second heat treatment (1223K-48 hours). It is a graph which shows the relationship between temperature and elongation about 2 samples.

Claims (13)

Si: 5.1 to 9.2 at%, Ti: 5 to 16 at%, Nb: 0.5 to 10 at%, B: 0 to 1000 ppm by weight, the balance is made of Ni except impurities, and the L1 ₂ phase Ni ₃ Si—Ni ₃ Ti—Ni ₃ Nb based dual phase structure having two phase coexistence composed of D0 ₂₄ phase or three phase coexistence composed of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase Intermetallic compound. The Si content is 5.1 to 9.2 at%, the Ti content is 5.1 to 11.2 at%, and the Nb content is 3.1 to 9.2 at%. The multiphase intermetallic compound according to claim 1. The Si content is 5.1 to 9.2 at%, the Ti content is 5.1 to 9.2 at%, and the Nb content is Nb: 3.1 to 9.2 at%. The multiphase intermetallic compound according to claim 1, wherein The Si content is 7.2 to 9.2 at%, the Ti content is 7.2 to 9.2 at%, and the Nb content is Nb: 3.1 to 5.1 at%. The multiphase intermetallic compound according to claim 1, wherein The multiphase intermetallic compound according to claim 1, wherein the content of B is 10 to 1000 ppm by weight. A high-temperature structural material comprising the multiphase intermetallic compound according to any one of claims 1 to 5 . The _{Ni 3 Si-Ni 3 Ti-} Ni 3 Nb -based mixed phase intermetallic compound tensile strength, tensile elongation, excellent in wear resistance and oxidation resistance, multi-phase according to any one of claims 1 to 6 Intermetallic compound . Si: 5.1 to 9.2 at%, Ti: 5 to 16 at%, Nb: 0.5 to 10 at%, B: 0 to 1000 ppm by weight, the balance is made of an ingot made of Ni excluding impurities,
Ni ₃ Si—Ni ₃ Ti comprising a step of performing a homogenization heat treatment at a temperature at which a two-phase coexisting state consisting of L1 ₂ phase and D0 ₂₄ phase or _a three-phase coexisting state consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase A method for producing a Ni ₃ Nb-based multiphase intermetallic compound. Si: 5.1 to 9.2 at%, Ti: 5 to 16 at%, Nb: 0.5 to 10 at%, B: 0 to 1000 ppm by weight, the balance is made of an ingot made of Ni excluding impurities,
Perform a first heat treatment that also serves as a homogenization heat treatment at a temperature that results in a single-phase state consisting of L1 ₂ phase or _a two-phase coexistence state consisting of L1 ₂ phase and D0 _a phase,
Ni ₃ Si—Ni ₃ Ti comprising a step of performing a second heat treatment at a temperature at which a two-phase coexistence state consisting of L1 ₂ phase and D0 ₂₄ phase or _a three-phase coexistence state consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase A method for producing a Ni ₃ Nb-based multiphase intermetallic compound. Si: 5.1 to 9.2 at%, Ti: 5 to 16 at%, Nb: 0.5 to 10 at%, B: 0 to 1000 ppm by weight, the balance is made of an ingot made of Ni excluding impurities,
A homogenization heat treatment is performed at a temperature at which a two-phase coexisting state consisting of L1 ₂ phase and D0 ₂₄ phase or _a three-phase coexisting state consisting of L1 ₂ phase, D0 ₂₄ phase and D0 _a phase,
The first heat treatment is performed at a temperature at which the single-phase state composed of the L1 ₂ phase or the two-phase coexistence state composed of the L1 ₂ phase and the D0 _a phase is performed.
Ni ₃ Si—Ni ₃ Ti— comprising a step of performing a second heat treatment at a temperature at which a two-phase coexisting state consisting of L1 ₂ phase and D0 ₂₄ phase or a three-phase coexisting state consisting of L1 ₂ phase, D0 ₂₄ phase and D0a phase A method for producing a Ni ₃ Nb-based multiphase intermetallic compound. The method according to claim 8 or 10, wherein the homogenization heat treatment is performed at 1073K to 1348K. The method according to claim 9 or 10, wherein the first heat treatment is performed at 1373 to 1523K, and the second heat treatment is performed at 1073 to 1348K. The method according to claim 9 or 10, wherein the temperature of the second heat treatment is 1123 to 1323K, and the time of the second heat treatment is 6 to 60 hours.